When Tom himself appeared in the erecting shop in working clothes the men might well be sure that something of importance was under way. There was another sign that never failed. Koku, the giant, was close at hand. The strange fellow had believed for a long time now that his beloved young “Master” was threatened by malign enemies, both of a physical and spiritual kind. No talking to Koku or explanation of religious matters could convince the giant that there were not actual “devils,” as well as evil influences, at work in the world. Tom had been in so many perils from certain evil people who were opposed to the Government during the war, and who were the young inventor’s personal enemies as well, that the poor savage expected harm to come to his master at any and all times. When Tom was working around machinery or engaged in any matter where there were other men about—especially rough looking men—Koku did not intend to be far away from Tom Swift. He watched the young fellow and all those who approached him with a gaze as sharp as that of a lynx. Sometimes Tom turned around quickly to find the giant almost at his elbow, his savage gaze enough to startle any one. Koku’s eyes had the quality of a cat’s. They narrowed to a wicked slit in the daytime, and were yellow. At night they expanded and were glowing, and it had often been proved that he could see farther and more distinctly in the dark than any American of European descent. As Tom moved about briskly, appointing each man his task, advising here and ordering there, Koku was sometimes quite put to it to keep within arm’s reach of his master. But, at least, he never lost sight of him, and the giant could move so quickly and lightly that he was seldom in anybody’s way. Having selected most of his mechanics with much care and after giving heedful attention to their characters as well as to their ability as workmen, Tom had no suspicion at this time that a single man in the works felt any enmity toward him. He laughed with his father and with Ned Newton, therefore, over Koku’s careful watch upon him and those about him. And yet, there arose a situation, totally unexpected, almost inexplicable, which might have been considered with justice a direct attempt to injure the young inventor. And in the thrilling action of the moment in question it seemed that Tom Swift would neither carry through his attempt to build a wonderful flying boat nor accomplish any other future marvel. Certain steel trusses were being arranged along the measured length of the floor of the shop devoted to the laying of the keel. The keel had reached Shopton in sections, and nobody outside the works could have guessed what the shining metal parts were as the trucks brought them from the railroad to the shops.